China

A tale of two towers

Two radically different ways to reach for the sky

China has a love affair with the skyscraper: five of the ten highest in the world are under construction in the Middle Kingdom. Two particularly prominent ones are scheduled to be finished in 2014. One, Shanghai Tower, would be China’s tallest building. Another, Sky City, an ambitious project in the interior city of Changsha, would leapfrog it to become the tallest in the world—if it is ever finished. The philosophies, technologies, timelines and business models involved in constructing Shanghai Tower and Sky City could not be more different. Together, they present a picture of the varied ways that innovation happens in China.

“I’m a guy who likes to be second in, not first,” declares Arthur Gensler. That may not sound sensational, but it works. Gensler, the architectural firm he co-founded in 1965, is now one of the world’s largest. It is also the driving force behind the public-private consortium building Shanghai Tower.

The tower will boast an array of small but useful features. Every ten or 15 storeys the architects have created a common space. Filled with shops and mingling areas, these are meant to build a sense of community. But they also enhance safety, as refuge floors under these lobbies can serve as safe harbours, thanks to fire-separation technology. Lifts designed to keep out smoke will, the architects hope, be safe to use in the event of a fire.

The building also expands the use of green techniques, from renewable energy to sky gardens. This is not the first building to feature a double skin or a twisted design, but it is the first to use them on a vast scale. The twist cuts the wind load by nearly a quarter, and so reduces the quantity of steel and concrete needed. Every step of the project has been vetted by outside experts, sometimes resulting in extensive (and costly) redesigns.

The tortoise and the hare

If the Shanghai Tower takes China’s tested path of incremental enhancements, Sky City represents the opposite. It hopes to take a great leap forward by harnessing China’s prowess at fast and frugal engineering and business-model reinvention.

Broad Group, the firm behind this effort, made its name building air-conditioning systems. But it has also developed novel prefabrication techniques that have allowed it to erect tallish buildings quickly. In January 2012 it put up a 30-storey hotel in just 15 days. The time-lapse footage of that feat has been viewed on YouTube millions of times.

Now Zhang Yue, the billionaire behind Broad, says he plans to erect Sky City in four months. If it reaches the planned 838 metres it will be ten metres taller than Dubai’s Burj Khalifa, at present the world’s tallest building. He claims his project is financed without government support. The first 15 floors of the 202-storey building will have offices, a school and a hospital, and the top floors a hotel, but most of the tower will be residential.

Questions abound. Broad first broke ground on the site in July 2013, but regulatory uncertainty soon halted work. Will regulators allow Broad to complete the project? Can huge modules be lifted quickly and safely to such heights? Will the public believe the building to be safe?

Mr Zhang seems to understand that the risk of failure is part of innovation. He says “factory architecture”, as he calls his approach, involves scary breakthroughs. Even if they fail, he suggests, his firm’s bold efforts “deserve sympathy”.

For Mr Gensler, failure is not an option. The Shanghai Tower project “is not going to fail because it is made up of incremental, not breakthrough, innovations,” he insists. “Like the pyramids, this building is going to be around for ever.”